The PnP BIOS may be wandering into segement 0x40. If that is the case, this
patch should fix the problem. I do not have a buggy system so I cannot test
this patch but I'd be intersted to hear the results. If you have a system that
has caused pnpbios problems in the past, I recommend you try this patch. If it
works, the system will not panic on startup. This patch is against 2.5.59 and
separate from my other recent patches.
--- a/drivers/pnp/pnpbios/core.c Fri Jan 31 16:59:57 2003
+++ b/drivers/pnp/pnpbios/core.c Fri Jan 31 17:01:07 2003
@@ -142,11 +142,13 @@
set_limit(cpu_gdt_table[cpu][(selname) >> 3], size); \
} while(0)
+static struct desc_struct bad_bios_desc = { 0, 0x00409200 };
+
/*
* At some point we want to use this stack frame pointer to unwind
- * after PnP BIOS oopses.
+ * after PnP BIOS oopses.
*/
-
+
u32 pnp_bios_fault_esp;
u32 pnp_bios_fault_eip;
u32 pnp_bios_is_utter_crap = 0;
@@ -160,6 +162,8 @@
{
unsigned long flags;
u16 status;
+ struct desc_struct save_desc_40;
+ int cpu;
/*
* PnP BIOSes are generally not terribly re-entrant.
@@ -168,6 +172,10 @@
if(pnp_bios_is_utter_crap)
return PNP_FUNCTION_NOT_SUPPORTED;
+ cpu = get_cpu();
+ save_desc_40 = cpu_gdt_table[cpu][0x40 / 8];
+ cpu_gdt_table[cpu][0x40 / 8] = bad_bios_desc;
+
/* On some boxes IRQ's during PnP BIOS calls are deadly. */
spin_lock_irqsave(&pnp_bios_lock, flags);
@@ -207,6 +215,9 @@
: "memory"
);
spin_unlock_irqrestore(&pnp_bios_lock, flags);
+
+ cpu_gdt_table[cpu][0x40 / 8] = save_desc_40;
+ put_cpu();
/* If we get here and this is set then the PnP BIOS faulted on us. */
if(pnp_bios_is_utter_crap)
@@ -1431,7 +1442,7 @@
* from devices that are can only be static such as
* those controlled by the "system" driver.
*/
- if (pnp_bios_get_dev_node(&nodenum, (char )1, node))
+ if (pnp_bios_get_dev_node(&nodenum, (char )0, node))
break;
nodes_got++;
dev = pnpbios_kmalloc(sizeof (struct pnp_dev), GFP_KERNEL);
@@ -1563,6 +1574,8 @@
pnp_bios_callpoint.segment = PNP_CS16;
pnp_bios_hdr = check;
+ set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
+ _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
for(i=0; i < NR_CPUS; i++)
{
Q2_SET_SEL(i, PNP_CS32, &pnp_bios_callfunc, 64 * 1024);
-
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This archive was generated by hypermail 2b29 : Fri Feb 07 2003 - 22:00:10 EST